1. Field of the Invention
The present invention relates in general to valve tappet assemblies for internal combustion engines.
2. Description of the Related Art
Various valve tappet assemblies have been developed for internal combustion engines. Hydraulic valve tappet assemblies have been developed for engines having relatively low revolutions per minute. See, for example, Vitalini, U.S. Pat. No. 1,965,517; Daisley U.S. Pat. No. 2,116,749; Voorhies, U.S. Pat. No. 2,237,854; Voorhies, U.S. Pat. No. 2,272,074; Meinecke, U.S. Pat. No. 2,484,109; Meinecke, U.S. Pat. No. 2,614,547; Voorhies, U.S. Pat. No. 2,688,318; Williams, U.S. Pat. No. 2,931,347; Wood, U.S. Pat. No. 2,966,151; Lesher, U.S. Pat. No. 3,142,290; Kuchen, U.S. Pat. No. 3,262,434; Cornell, U.S. Pat. No. 3,291,107; Rhoads, U.S. Pat. No. 3,304,925; Donnelly, U.S. Pat. No. 3,406,668; Humphreys, U.S. Pat. No. 3,498,273; Dadd, U.S. Pat. No. 3,516,393; Rhoads, U.S. Pat. No. 3,921,609; Brown, U.S. Pat. No. 3,967,602; and Svihlik, U.S. Pat. No. 4,184,464. Such hydraulic valve tappet assemblies typically have relatively flat cam engaging surfaces which are designed to rotate relative to the valve stems.
Roller valve tappet assemblies have been designed for use with engines having relatively high revolutions per minute. While such roller valve tappet assemblies reduce the valve tappet wear associated with high speed engines, it is desirable to prevent rotation of the roller valve tappet assemblies. Crane, U.S. Pat. No. 3,108,580 discloses a non-rotatable roller valve tappet apparatus which utilizes an alignment bar 26 extending between two adjacent tappets to prevent rotation of the tappets relative to one another and therefore, relative to the longitudinal axis of the valve stem.
The present invention is not disclosed or suggested by the above prior art.